Scalable video coding (SVC) is a video encoding technique, in which a video sequence is encoded as a hierarchy of video layers consisting of one base layer and at least one enhancement layer. This type of video encoding allows a video transmission system to adapt to changes in channel conditions by selectively discarding video layers or packets. Numerous existing algorithms for discarding video layers with reducing bandwidth exist. However, such algorithms, on their own, rely on the base layer rate being satisfied at all times.
If the base layer rate cannot be satisfied under a given channel condition, the base layer will not be transmitted. In that case, video playback will not be possible at the receiver—in fact, no video data will have been transmitted.